1970 GB Halfpenny "TRIAL" Pattern

7Jaguars

Here is a mysterious coin that I got some 3 or 4 years ago at auction. I then had it slabbed ATS and promptly forgot to weigh it. In any case, there was as readers may know much mint sport going on at the Royal Mint but this coin is an OMS (off metal strike) and clearly marked "TRIAL" on both obverse and reverse. What possible use would there be for such a coin after the decimal system was abandoned and phasing out as early as 1968?
Well, it may have been an experimental alloy for upcoming CuNi coins. However the new 10 Pence was the exact specifications as the older CuNi florin at 11.31 gms. so the alloy was not going to be messed with, so that explanation does not make sense. I don't really know, but it is an attractive coin and would seem to be of specimen status and not a simple mint state coin.
BTW, they indicated across the street that it was struck of iron but I believe that to NOT be the case based on metal appearance; and yet in another twist the coin is magnetic through the perspex of the TPG slab:

Apparent light scratches are on the plastic perspex holder and not the coin. I took two pictures of the obverse to try to show the coin better.

robp2

As per the conversation I had with Graham Dyer a few year ago and posted on the Predecimal forum, he said forget the denomination. These strikes were all about testing a metal mix and not necessarily struck in the year indicated - just like my sample half-crown in steel which he said was made in the early 1980s, long after the halfcrown ceased to be relevant.

7Jaguars

Yes, I do recall a 1952 dated "half crown" pattern in similar metal. Interesting point you have there Rob. Have you weighed your specimen posted? I really would like to get an XRF analysis on any of these...

SYRACUSIAN

@7Jaguars , what says the 3 year old label? (grade included). And would it be worth reholdering it now, in order to have more info on it, even if it is you who provides it to them?

7Jaguars

It is MS67 and stated "iron" on label. Not sure how it is not a satin specimen. Young Rob seems to speculate that it was done as an alloy test for the upcoming predecimal issues, which sounds reasonable except why in the world would they issue an iron based coin into the damp climes of Britain?

robp2

I am suggesting an alloy test based on Graham Dyer's assertion that my stainless halfcrown was done to test the metal and had nothing to do with the denomination. Our small denominations are now struck in clad steel, so yes they would use an iron based coinage. You must also remember the Royal Mint doesn't strike exclusively for the UK.

syl

If all those scratches are on the coin and not the holder, there is no way that it even approaches MS67. You need to XRF it to find the alloy.

robp2

The grade is immaterial and a distraction because all these oddballs are unique or nearly so. The important bit is establishing the reason why they were made in the first place.

When I bought the halfcrown posted above at the Adams halfcrown sale in 2005, I had mentally marked it down as a possible pattern to be introduced early in the reign. I was wrong. It needed the input of someone with intimate knowledge of the mint workings to clarify why and when it was made (testing a stainless steel flan in the 1980s). The solution might be to approach the RM. Knowing the alloy would also help the RM establish when it was made if there are any trace elements specific to a particular mix, as they will have a record of the various components. You need to break it out.

7Jaguars

Syl, the coin in hand is truly a beauty for such a an alloy with swirling luster and the only lines/scratches are on the holder or die prep lines. I would vote for a specimen status as it is certainly the equal of some of the KN specimen pieces now sold on occasion on ebay.
But seriously, Rob has a good point about tracking down alloys versus time.
As a footnote I bid on several of the Adams' halfcrowns and did not feel your coin to be per se an half crown pattern so did not contend & am glad you got it.